Almost half of all deaths in children under the age of five are linked to undernutrition. Most of these occur in the developing world. There is therefore an urgent need to address this pressing issue which costs the lives of millions of children every year. And as detailed below, the answer is not as simple as providing more food.
In a new Gut review, led by IGHI lecturer Dr Alex Thompson, scientists explore the role that technology could play in improving understanding, management and prevention of this complex condition, with a focus on low- and middle-income countries.
We caught up with Dr Thompson to find out more.
Your paper centres on the fact that there is more to undernutrition than lack of food. What other factors contribute to undernutrition?
Yes – it seems counterintuitive, but undernutrition is much more complicated than lack of food. And it can’t be adequately solved simply by administering additional food either. It’s believed that this is because there is a breakdown in the way the gut functions. This breakdown is referred to as Environmental Enteropathy (EE) and is a result of a combination of factors including lack of food, poor hygiene and repeated infections. The result of this insult on the gut is that the gut’s ability to process and absorb nutrients is restricted. This restriction appears to persist even when sufficient food is provided, meaning that undernutrition cannot be combated simply through the provision of food.
Together, this means that we need better ways to address undernutrition and better ways to assess and study EE.
How is EE typically assessed?
Not very well. There are a number of techniques and devices that have been used to assess EE, but they are typically invasive, unreliable or expensive. As an example, EE can be assessed by taking biopsies from the gut and investigating the structure of the intestinal wall. This is an expensive and invasive procedure that requires endoscopy. Alternatively, there are several tests that assess the permeability (or leakiness) of the intestine that have been applied to EE. These typically require the collection of urine samples at specific times. While this sounds simple, it can in fact be very challenging in young children (who are particularly at risk of undernutrition and EE). As a result, these permeability tests are usually very unreliable.
Your review highlights a range of technologies that could help better assess gut function at the point of care. What kinds of approaches are these?
We discuss several diagnostic technologies that we think will help provide better assessment of gut function in undernutrition. These range from capsules that are swallowed by the patient and provide images, measurements, or samples from the gut to portable and even wearable sensors that can assess important aspects of gut function including permeability, digestion, absorption, and even the make-up of the gut bacteria.
Undernutrition particularly affects low- and middle-income countries. Are these technologies suitable for deployment in these settings?
Yes. We intentionally highlighted devices and techniques that are (or soon will be) suitable for point-of-care use in low-income settings. That means systems that do not require advanced infrastructure that is usually only available in large hospitals, but which can instead be deployed in small, rural health facilities or even in the home. In addition, many of the devices that we discuss are low-cost and user-friendly, further highlighting their potential for use in poor countries where undernutrition is most prevalent.
Beyond improved diagnostics, how else might these technologies play a role in tackling undernutrition?
One of the biggest challenges in undernutrition is actually in monitoring responses to interventions. For example, if we give undernourished children more food and access to clean water, how do we know if that has truly improved their nutritional status? As the technologies highlighted in this paper are suitable for point-of-care use in low-income settings, they may also provide opportunities to monitor the effects of EE and undernutrition over long periods of time. In turn, this would allow us to better assess the impact of interventions designed to address undernutrition. This would be hugely useful in the longer-term fight against undernutrition, which at present still kills as many as three million children every year.
The paper, ‘Understanding the role of the gut in undernutrition: what can technology tell us?’ has been published in the BMJ journal Gut. Access the paper here.
Dr Alex Thompson is a Lecturer in Sensing in Cancer at the Hamlyn Centre, Institute of Global Health Innovation